Dražice OKC 500 NTR/1MPa, OKC 300 NTRR/1MPa, OKC 400 NTRR/1MPa, OKC 400 NTR/1MPa, OKC 500 NTRR/1MPa Operation And Installation Manual

OPERATION AND

INSTALLATION MANUAL

INDIRECT WATER HEATERS

OKC 300 NTR/1MPa OKC 300 NTRR/1MPa

OKC 400 NTR/1MPa OKC 400 NTRR/1MPa
OKC 500 NTR/1MPa OKC 500 NTRR/1MPa
OKC 750 NTR/1MPa OKC 750 NTRR/1MPa
OKC 1000 NTR/1MPa OKC 1000 NTRR/1MPa

Družstevní závody Dražice - strojírna s.r.o.

Dražice 69, 294 71 Benátky nad Jizerou
tel.: +420 / 326 370 990
fax: +420 / 326 370 980
e-mail: [e-mail]

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CONTENT

1 TECHNICAL SPECIFICATION OF PRODUCT ................................................................................................. 4

1.1 FUNCTION DESCRIPTION ................................................................................................................... 4

1.2 PRODUCT DESCRIPTION .................................................................................................................... 4

1.3 TECHNICAL PARAMETERS .................................................................................................................. 5

1.3.1 TECHNICAL PARAMETERS OF HEATERS WITH ONE EXCHANGER .............................................. 5

1.3.2 TECHNICAL PARAMETERS OF HEATERS WITH TWO EXCHANGERS ........................................... 6

1.3.3 PERFORMANCE DATA ................................................................................................................ 7

1.3.4 PRESSURE LOSSES ...................................................................................................................... 9

1.4 CONSTRUCTION AND GENERAL HEATER DIMENSIONS ................................................................... 10

2 OPERATION AND FITTING INSTRUCTION ................................................................................................. 15

2.1 OPERATING CONDITIONS ................................................................................................................ 15

2.2 CONNECTING A HEATER TO A HOT WATER DISTRIBUTION ............................................................ 15

2.3 PLUMBING FIXTURE ......................................................................................................................... 16

2.4 CONNECTING A HEATER TO A HEATING SYSTEM ............................................................................ 17

2.5 PUTTING THE HEATER INTO OPERATION ........................................................................................ 18

2.6 PUTTING OUT OF SERVICE, DISCHARGE .......................................................................................... 19

2.7 INSPECTION, MAINTENANCE & CARE FOR THE APPLIANCE ............................................................ 20

2.8 SPARE PARTS.................................................................................................................................... 21

3 IMPORTANT NOTICES .............................................................................................................................. 21

3.1

INSTALLATION REGULATIONS.......................................................................................................... 21

3.2 DISPOSAL OF PACKAGING MATERIAL AND FUNCTIONLESS PRODUCT ........................................... 22

4 ASSEMBLY GUIDE FOR ZIP-FASTENER INSULATION (FOR 750 AND 1000 LITRES) ................................... 23

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Meaning of pictograms used in Manual

Important information for heater users.

Recommendations of manufacturer, observance of which will ensure trouble-free

operation and long service life of the product.

CAUTION!

Important notice to be observed.

READ CAREFULLY THE BELOW INSTRUCTIONS PRIOR TO THE INSTALLATION

THE HEATER!

Dear Customer,

The Works Cooperative of Dražice – Machine Plant, Ltd., would

like to thank you for your decision to use a product of our

brand. With this guide, we will introduce you to the use,
construction, maintenance and other information on electrical
water heaters.

The manufacturer reserves the right for engineering modification of the product. The product is designed

for permanent contact with drinkable water.

It is recommended to use the product in indoor environment with air temperatures from +2°C to 45°C
and a relative humidity up to 80%.

Product’s reliability and safety is proven by tests implemented by the Engineering Test Institute in Brno.

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1 TECHNICAL SPECIFICATION OF PRODUCT

1.1 FUNCTION DESCRIPTION

Indirect stationary heaters lines NTR and NTRR are used for water heating in conjunction with another
source of heating water, most often a gas boiler. The NTRR types combine two sources of heating water
(gas boiler + a solar system or a heat pump). Their nominal performance provides sufficient amount of hot
water for large flat units, premises, restaurants, and similar establishments.

In case of increased hot water consumption, these tanks heat water continuously, operating similarly to
flow heaters.

1.2 PRODUCT DESCRIPTION

The heater tank is welded from a steel sheet; it is entirely coated with hot water resistant enamel.
Magnesium anode is added in the vessel as an additional protection against corrosion, which regulates the
electric potential of the inside of the vessel and thus reduces the effects of corrosion. Inside the tank, hot
and cold water and circulation pipes; a thermostat well; and either one or two spiral steel pipe heat
exchangers (enamelled on the outside) are all welded on.

The pipe heat exchanger is only intended for the heating circuit.

On the heater side, there is a cleaning and revision opening ending with a 110 mm flange; the clearance
including eight M8 bolts is 150 mm – 300 to 500 litres, for 180 mm clearance the spacing of ten bolts is 225
mm – 750 to 1000 litres. A heating unit with various output containing an operating and safety thermostat
can be mounted in the opening. The NTR series heaters are equipped with a G 1 1/2“ aperture for in­screwing an additional heating element. Such version is used when the heater is connected to either a solar
system or a system with a heat pump, to heat water in the upper part of the heater to the temperature
required. The tank is insulated with 50-80 mm of polyurethane freon-free foam. The tank shell is made of a
steel sheet painted with a powder coating (the 400-500 l types only, other are in plastic), and the
connecting parts are metal-coated.

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1.3 TECHNICAL PARAMETERS

1.3.1 TECHNICAL PARAMETERS OF HEATERS WITH ONE EXCHANGER

TYPE

OKC 300

NTR/1MPa

OKC 400

NTR/1MPa

OKC 500

NTR/1MPa

OKC 750

NTR/1MPa

OKC 1000

NTR/1MPa

Tank capacity

l

300

385

485

750

975

Diameter

mm

670

700

700

910

1010

Weight

kg

108

123

173

253

337

Operating hot service

water pressure

MPa 1 1 1 1 1

Operating heating

water pressure

MPa 1,6 1,6 1,6 1,6 1,6

Max temperature of

heating water

°C 110 110 110 110 110

Max temperature of

hot service water

°C 95 95 95 95 95

Exchanger heat

surface

m2 1,5 1,8 1,9 3,7 4,5

Exchanger

performance at
temperature drop
80/60 °C

kW 35 57 65 99 110

Performance number

according to DIN 4708

NL 8 15,2 19,1 30,5 38,8

Permanent HSW*

performance

l/h 1100 1395 1590 2440 2715

HSW* heating time

by exchanger at
temperature drop
80/60 °C

min 24 20 23 24 26

* HSW – Hot service water 45 °C

Table 1

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1.3.2 TECHNICAL PARAMETERS OF HEATERS WITH TWO EXCHANGERS

TYPE

OKC 300

NTRR/1MPa

OKC 400

NTRR/1MPa

OKC 500

NTRR/1MPa

OKC 750

NTRR/1MPa

OKC 1000

NTRR/1MPa

Tank capacity

l

295

380

470

750

995

Diameter

mm

670

700

700

910

1010

Weight

kg

124

144

183

245

315

Operating hot service

water pressure

MPa 1 1 1 1 1

Operating heating

water pressure

MPa 1,6 1,6 1,6 1,6 1,6

Max temperature of

heating water

°C 110 110 110 110 110

Max temperature of

hot service water

°C 95 95 95 95 95

Upper exchanger

heat surface

m2 1 1,05 1,3 1,17 1,12

Lower exchanger

heat surface

m2 1,5 1,8 1,9 1,93 2,45

Lower/upper

exchanger
performance at
temperature drop
80/60 °C

kW 35/27 57/31 65/40 60/33 76/32

Performance number

according to DIN
4708 upper
exchanger

NL 2,9 3,4 5,9 6,2 7,1

Performance number

according to DIN
4708 lower
exchanger

NL 4,2 15,2 19,1 21 26

Permanent HSW

performance* of
lower exchanger

l/h 1100 1395 1590 1460 1490

Permanent HSW

performance* of
upper exchanger

l/h 670 740 970 815 780

HSW* heating time by
exchanger at
temperature drop
80/60 °C

(lower/upper)

min 24/16 20/14 23/16 37/28 43/37

*HSW – Hot service water 45 °C

Table 2

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cwt = 10°C

cwt =10°C hwt = 45°C

mth= 50°C mth = 60°C mth = 50°C mth = 60°C

UE LE UE LE
°C - - - - l/h kW l/h kW l/h kW l/h kW l/10min l/10min m3/h
50 1,1 1,8 - - 431 17,1 259 10,4 - - - - 111 ­60 1,3 2,2 1,6 2,6 594 24 348 14,1 446 18 261 10,6 127 152
70 1,7 2,7 2 3,3 818 33,6 468 19,1 614 25,2 351 14,3 145 174
80 2,1 3,4 2,5 4,1 1086 44,2 629 25,9 815 33,2 472 19,4 166 199
90 2,7 4,4 3,2 5,3 1299 52,6 757 30,6 974 39,5 568 23 161 217
50 3,2 5,3 - - 493 19,6 305 12,2 - - - - 221 -

60 3,7 6 4,4 7,2 679 27,4 410 16,6 509 20,6 308 12,4 243 292
70 4,2 6,9 5 8,2 935 38,4 551 22,5 701 28,8 413 16,9 268 321
80 4,8 7,8 5,7 9,4 1241 50,5 740 30,5 931 37,9 555 22,9 294 353
90 5,8 9,6 7 11,5 1485 60,1 891 26 1114 45,1 668 19,5 316 379
50 3,8 6,2 - - 583 23,5 395 15,9 - - - - 332 ­60 4,7 7,8 5,7 9,3 790 32 531 21,5 593 24 399 16,1 360 432

70 5,9 9,7 7,1 11,7 1070 43,5 715 29,2 803 32,6 536 21,9 390 468
80 7,4 12,2 8,9 14,7 1430 58 962 39,6 1073 43,5 722 29,7 423 507

90 9 14,8 10,8 17,8 1720 70 1157 46,8 1290 52,5 868 35,1 450 540

2,7/2,7

3,0/3,0

3,0/3,0

Heating

water flow

Flow in 10 minutes

NL Power Factor

at

Permanent hot water output

Inlet

heating

water

temperatu

re

Type

LE

UE

OKC 300 NTRR/1MP a

OKC 400 NTRR/1MP a

OKC 500 NTRR/1MP a

cwt = 10°C

hwt = 45°C

hwt = 60°C

LE

UE

hwt = 45°C

cwt = 10°C

hwt = 45°C cwt =10°C hwt = 45°C

mth = 50°C mth = 60°C mth = 50°C mth = 60°C

°C - - l/h kW l/h kW l/10min l/10min m3/h
60 4,3 - 617 25,1 - - 290 ­70 5,3 8,4 888 36,1 622 26,8 322 403
80 5,3 8,4 1100 47,4 816 39,8 358 448
90 5,3 8,4 1451 59 1015 52,5 398 497
60 6,8 - 738 29,9 - - 399 ­70 10,1 12,8 990 43,2 745 32,1 443 554
80 10,1 15,2 1394 56,7 976 47,6 492 615
90 10,1 15,2 1733 70,4 1212 62,7 547 684
60 11,3 - 842 34,2 - - 500 ­70 15,2 15,8 1210 49,2 847 36,7 556 694
80 15,2 19,1 1584 64,4 1109 54,2 617 771
90 15,2 19,1 1965 79,9 1376 71,2 686 858
60 12,9 - 1279 52 - - 817 -

70 15,4 25,6 1828 74 1364 56 848 1060
80 18,3 30,5 2437 99 2065 84 880 1100

90 21 35 3046 124 2719 111 928 1160
60 16,6 - 1424 58 - - 862 -

70 19,7 32,8 2034 83 1518 62 908 1135
80 23,3 38,8 2712 110 2298 94 957 1197
90 27 45 3390 138 3026 123 1003 1254

OKC 400 NTR/1MPa

OKC 500 NTR/1MPa

OKC 750 NTR/1MPa

OKC 1000 NTR/1MPa

Type

OKC 300 NTR/1MPa

Inlet

heating

water

temperatur

e

NL Pow er Factor

at

Permanent hot water output

Flow in 10 minutes

Heating

water flow

hwt = 45°C

hwt = 60°C

cwt = 10°C

3

5

6

2,7

3

1.3.3 PERFORMANCE DATA

Table 3

UE – upper exchanger

LE– lower exchanger

cwt – cold water temperature

hwt – hot water temperature
mth – medium temperature of the

heater

Table 4

UE – upper exchanger

LE – lower exchanger

cwt – cold water temperature

hwt – hot water temperature
mth – medium temperature of the

heater